An explosion went off at toymaker Mattel, Inc.’s El Segundo design center this morning.

The bang was heard at around 7:00 am and the city’s police and fire departments were alerted and responded to the scene. The Los Angeles County Sheriff Office’s bomb squad was also called in.

The blast did not seem to injure anyone and seems to have originated from a homemade explosive housed in a plastic bottle. Authorities evacuated the building during their investigation, which turned up the plastic debris. Employees were able to come in to work shortly thereafter.

The investigation is being handled as a crime. Due to recent events, homemade explosives should be taken seriously. Police encourage anyone with information about this bombing to contact Detective Eric Atkinson at (310) 524-2216.